This is one of the standard topics relevant to those who model intermolecular forces, for computer simulation and/or theory of the liquid state. The molecular charge distribution is typically modelled by a multipole expansion (sometimes, by a set of distributed multipoles) and the electrostatic interactions between a pair of molecules are calculated in just the way you describe.

Two of the standard works in the field are *The Theory of Intermolecular Forces* by Anthony Stone, second edition (Oxford University press, 2013), and *Theory of Molecular Fluids* by CG Gray and KE Gubbins (Clarendon Press 1984). Both texts are very clearly written, go into great detail, and give formulations based on both Cartesian tensors and spherical tensors. 

In both cases, they go much further, discussing induction and dispersion interactions and so on, but these may not be so relevant to your application.